Lee Yoon-Sung (Lee Min-Ho) works at the Blue House’s National Communication Network Team and received his Ph.D at M.I.T. Kim Na-Na (Park Min-Young) is a bodyguard at the South Korean president’s residence, the Blue House . Na-Na lost her parents by car accident since than she made a living by doing
part time jobs. She became a bodyguard at the Blue House. Kim YoongSu (Lee Jun Hyuk) is set to play a prosecutor who has a dream to become an attorney general. He’s described as a workaholic who doesn’t believe in love and intends to marry a woman with promising background. The condition changes after he meets a Blue House body guard “Kim Na-na (Park) and falls in love to her. Unfortunately, she has her own love interest, a member of international communication team at Blue House “Lee Yoon-Sung” . The three later get entangled in love triangle relationship. (Goo Hara) will play a spunky young woman who is also the president’s daughter. She is trying hard to get into college after failed in the first time. Ko Ki-Joon (Lee Kwang Soo) an inflexible and unsociable character who is actually a genius computer engineer at Blue House where Yoon-sung and Na-na work as well. Jin Soo Hee (Hwang Sun Hee), an alumna of the De
partment of Theater at Sangmyung University and IHQ’s Acting Training Center C.A.S.T and a veterinarian. She is a character who embodies a cold outward appearance but possesses a warm heart. As the best friend of “City Hunter” Yoon-Sung (Lee Min Ho), “Jin Soo Hee” considerately comforts “City Hunter” who is a perfectionist in terms of work but suffers from loneliness unknown to others.